Plywood patching machine



1937- w. J. MILLER 2,091,450

PLYWOOD PATCHING MACHINE Filed March 20, 1936 2 Sheets-Sheet 2 IN V EN TOR.

Mil/am JAZZ/er A TTORNEY.

Patented Aug. 31, 1937 NT FFIQE PLYWOOD PATCHING MACHINE William J. Miller, Seattle, Wash, assignor to Ellicott Bay Mill 00., Seattle, Wash, a corporation of Washington Application March 20,

12 Claims.

This, invention relates to apparatus for patching plywood and the general object of this invention is to provide simple and eflicient means for quickly and easily routing out imperfect spots in the outer or surface ply of Wood veneer or plywood preparatory to patching the same.

Wood veneer, usually called. plywood, often has imperfect spots, as knots, pitch pockets, and the like in the surface ply. In some commercial grades of plywood an average of from five to ten imperfect spots will be found in a surface ply of each four by eight foot panel after the panel has been glued up. These imperfect spots are usually relatively small and are eliminated by routing out the imperfect spot and inserting and gluing in of a patch formed of the same material as the surface ply of the panel. It has been found that a patch of this nature, when correctly fitted, glued in and sanded is very inconspicuous, and that a patch of generally elliptical shape is less conspicuous than if the patch is made of other shapes. It is therefore desirable, in eliminating a defective spot from a surface panel, to first provide a recess of generally elliptical shape in the panel and then secure a patch of similar shape in the recess.

it is an object of this invention to provide simple and eflicient means for routing out recesses of generally elliptical shape in the surface plys of plywood panels and to further provide means by which these recesses are made of uniform shape and size so that patches of predetermined shape and size will fit the recesses snugly and correctly and will not be noticeable on the finished panel.

Another object of this invention is to provide means by which recesses of generally elliptical shape can be very rapidly and easily routed out of the surface plies of veneer panels thus reducing the time and labor necessary to: do this patching work and avoiding unnecessary delays in the manufacture of plywood in veneer plants.

Other and more specific objects of the invention will be apparent from the following description taken in connection with the accompanying drawings.

In the drawings Fig. 1 is an elevation of plywood patching apparatus constructed in accordance with this invention.

2 is a plan view on a larger scale of the same with parts shown in section substantially on broken line 2-2 of Fig. 1.

Fig. 3 is a detached sectional view of a pneumatic cylinder and control valve therefor.

Fig. 4 is a plan View of a fragment of a plywood 1936, Serial No. 69,788

panel having a recess of generally cylindrical shape routed out of an outside ply thereof in accordance with this invention.

Fig. 5 is a sectional view on broken line 5-5 of Fig. 4.

Fig. 6 is a perspective view of a patch adapted for use as an insert in the recess in the panel shown in Figs. 4 and 5.

Figs. '7, 8 and 9 are fragmentary plan views of modified forms of the invention.

Like reference numerals designate like parts throughout the several views.

In accordance with my invention I provide a plate it, which may be of dislike shape as shown in Fig. 2. This plate it is adapted to be pressed against or raised clear of a plywood panel H which rests on a table l2. The plate H3 is provided with an opening it which is larger than the maximum size of recess which the machine is designed to rout out. This opening 13 provides clearance through which a router bit or tool M may operate. The router bit I4 is supported in a chuck means If: which is connected with a flexible driven shaft it. The use of the flexible driven shaft l6 makes it possible to move the router bit sidewise freely within certain limits as hereinafter set forth.

Means for limiting and governing the sidewise movement of the router bit M, see Figs. 1 and 2, is provided in the nature of two radius links H and 58, each having one end pivotally connected with the chuck means which receives the router b-it M. The radius links I! and i6 extend in opposite directions from the chuck means l5.

Two link members l9 and 20 have their respective rear end portions pivotally connected with pivot members 2| and 22, which pivot members are rigidly secured to the plate Ill at points to the rear of the opening I3. The link members it and 26 extend forwardly on opposite sides of the chuck means l5 and are respectively connected by pivots 23 and 24 with the radius links it and it. A fixed stop member 25, on the plate it limits the swinging movement of link 20 toward the opening l3 in the plate lil. An extension 26 is provided on the forward end of the link W. This extension 26 is adapted to engage with, preferably adjustable, stop means to limit the swinging movement of the link IS. The adjustable stop means shown in the drawings consists of a stop bar 2'! mounted for rotative movement in a bracket 23. Bracket 28 is rigidly secured to plate l0. One end of stop bar 21 protrudes from bracket '28 and has preferably three stop members 29 provided thereon at longitudinal and angular intervals. Each stop member 28 may consist of a lug on bar 217 with a set screw therein. By adjusting the stop bar 5 2'1 angularly any selected one of the three stop members Bil may be positioned in the path of the extension 26 to serve as a stop for the link is and mechanism connected therewith. An enlarged head or finger piece 38 on one end of 10 the stop bar 24 is provided with a pin 3! adapted to fit within suitably spaced holes 32 in the adjacent end portion of the bracket 28 providing means for holding the stop bar 2i in difierent angular positions to selectively position any de- 5 sired one of the stop members 29 in the path of the extension 25. A spring 33 on the stop bar '5 yieldingly holds the head member 38 against the end of the bracket 28 permitting endwise movement of the stop bar for the purpose of dis- 20 engaging the pin 5i from the holes 32 when adjusting said stop bar.

A lever member 34 is pivotally connected with the chuck l5 and extends in two directions therefrom. One end of the lever member 34 has a 25 hand hold 35 thereon. The other end of the lever member 34 is connected by a pivot 35 with one end portion of a link 31. The other end portion of the link 8'! is pivoted on a pivot member 38 which is fixedly secured to the base plate EU.

30 By moving the lever 34 it is possible to move the router bit l4 and chuck l5 freely within certain limits of movement permitted by the fixed stop means 25 and adjustable stop means 29. This makes it possible to traverse with the router bit 35 an elliptical area the sides of which are arcs described from the centers of pivots 25 and 24 when said pivots are in the innermost positions which they are permitted to assume by the respective stop means 29 and 25. The ends of the elliptical 40 area traversed by the router bit are determined by the circumference of the router bit.

The plate It is provided with the opening l3 through which the router bit l4 operates. This opening l3 may be of generally elliptical shape 45 as shown in Fig. 2, and is substantially larger than the largest recess which is to be routed out of the plywood and is also large enough to preclude all possibility of the rout-er bit contacting the plate It).

The frame plate H) together with the mechanism assembled thereon is vertically movable and is supported from an overhead transverse track bar 40. The track bar 48 is supported by an upright member 41 which extends upwardly at 55 one side of the table. The upright member 4! is secured to a carrier member 42 having wheels 43 operatively disposed in track members 44 positioned below and extending longitudinally of the table 5 2. This provides a supporting means which 60 may be moved in one direction relative to the table l2 while the mechanism supported on the overhead track bar 48 may be moved relative to the table in a direction at right angles to the direction of movement of the supporting means. 65 The upright member 4! may be offset as respects the plate I8 and track member 48 far enough to permit the plate It to be moved over the edge of the table past which the member 44 protrudes.

A carriage 45 having wheels 48 is movable on 70 the track bar 40. A supporting post 47 is fixedly secured to the carriage 45 and extends downwardly therefrom to form a support for the plate l8 and mechanism thereon. The post 4'! projects into the upper end of a pneumatic cylinder 48 7 and is fixedly secured to a piston 49 which is operatively disposed within said cylinder. The cylinder 48 is rigidly connected with the plate It] by support means 50. This provides devices by which the plate l may be moved downwardly by admitting compressed air into the lower end portion of the cylinder 48 below the relatively fixed piston as and upwardly by admitting compressed air into the upper end portion of the cylinder 48 above the relatively fixed piston 49.-

Angular movement of the plate member [0 relative to the depending support 41 is prevented by an upright post which is rigid with the plate l8 and slidable vertically in a guide arm 52. The guide arm. 52 is rigid with the support 47.

The driving means for the router bit is preferably a motor 53 connected through a suitable transmission 54 and shaft 55 with the flexible shaft H5. The motor 53 and transmission 54 are mounted on a bracket 55 which is supported by an upright rod 51. The rod 51 extends downwardly through guides 58 and 59 on the carriage 45 and is secured to the vertically movable cylinder 48 thus providing supporting means by which the motor and transmission are moved vertically along with the plate l5 and mechanism thereon. A guide pin 55 on the bracket 55 is vertically movable in a guide member 5| which is. rigid with the carriage 45. This guide pin helps toguide and support the bracket 55 and prevents angular displacement of the same.

Preferably a compression spring 52 is provided on the upright rod 57 between the upper end of the guide member 59 and a collar 63 which is secured to said rod 5?. This spring 62 is strong enough to lift the plate It and mechanism thereon together with the bracket 56 and driving means carried thereby and to hold the same in an elevated position except when these parts are moved downwardly by the admission of air under pressure to the lower position of the cylinder 48.

Compressed air for vertically moving the plate 118 and mechanism carried thereby is supplied to a valve housing 54 through a compressed air supply conduit 65. The valve housing 64 has a r0- tary valve member 66 and is connected by one conduit 81 with the upper end portion of the cylinder 48 and by another conduit 53 with the lower end portion of the cylinder 48. The valve member 66 is operated by a valve operating handle 69 pivoted for oscillation in bearing means 10. The valve operating handle 69 is connected by a lever ii, a link 52 and a lever 13 with the valve to the lower end of the cylinder 48 and move the plate Iii down onto the plywood panel H. Upward movement of said valve operating handle 59 will admit compressed air to the upper end of the cylinder 48 and move the plate Ill upwardly clear of the plywood panel into a position as shown in Fig. 1. Upward movement of the plate i8 and parts carried thereby may be limited by engagement of the collar 63 on rod 51 with the guide member 58.

When the valve operating handle 69 is in the neutral position shown in Fig. 1, the top and bottom ends of the cylinder will both have pressure relief communication with the atmosphere through relief ports 14 and opening of air inlet pipe 55 will be closed.

The router bit is held down by the weight of the several parts connected therewith and by pressure exerted by the operator on the control lever 34 during the routing operation.

-in.their outer ends,.slots 11 which flt slidably over .fixed studs or pins 18 on the main plate H]. In :thisconstruction engagement of the outer ends of the slots 11 with the fixed studs or pins 18 stops or limits the movement of the router tool and determines the arcs forming the sides of the recesses which are routed out of the plywood .panel, the ends of said recesses having the same curvature as the circumference of the router bit. By providing for the adjustment of one or both of the pins 18 it is possible to vary the size wof the recess which will be routed out of the plywoodpanel. This may be done by providing a -..plurality of holes. 19- in the main plate ID for :u'receiving the pins 18.

In Fig. 8, I have shown another modified form of the invention which consists in slidably mount- .-ing the outer ends of radius links and 8| .in fixed stop means 82 pivotally mounted on the .main plate I0. An adjustable stop member 83 is provided on the outer end portion of one or 1 both of the radius links 80 and BI to engage the stop means 82 and limit the movement of the router bit.

V In Fig. 9, I have shown still another modified form .of the invention in which flexible connecters $841 and are used as radius means instead of the hereinbefore described radius links. The flexible connecters 84 and 85 are anchored at the ends to anchor means 86 and 81. A plurality of spaced apart stops 88 are provided on at least one of the flexible connecters providing means -to vary the size of the recess which is to be routed out.

Inthe operation of this device plywood panels Hare preferably fed or moved over the table .12 either manually or mechanically. An opera- .tor standing at the side of the table l2 spots the defects in the top ply of these panels, lowers the plate "I0 onto the panel with the opening 39 .in said plate positioned over the defect and, by .-moving the handle 34, causes the driven router .bit to traverse or cover a limited area of generally ellipticalshape thus routing out of the panel an elliptical recess 90 which includes the defective spot. As soon as the defective spot has been routed out the plate [0 and mechanism thereon is raised by manipulation of the valve operating handle. permitting movement of the panel or movement of the routing mechanism to another location over the panel. Preferably two of the units shown in Fig. 1, will be provided over each table to permit two operators to work on the same panels on opposite sides of the table.

When the plate In is lowered onto a plywood panel the pressure of the air will hold the plate very firmly in engagement with the panel thus holding the panel immovable.

The device is very rapid and very accurate in operation and leaves the panels in condition to have previously prepared conical shaped patches 9| glued therein. The elliptical recesses 90 extend lengthwise of the grain of the wood, as indicated in Fig. 4, and the curved markings of the grain. harmonize with the edges of the recesses so that ,the patches are very inconspicuous on the finished panel.

'Thecarriage 45 and mechanism carried thereby is. movablev along track bar 40 transversely of the table and the said track bar is movable longi- 75 tudinally of the table thus providing for quick and easy movement of the plate Ill to any desired location over the panel I I.

,The foregoing description and accompanying drawings. clearly disclose a preferred embodiment of my invention but it will be understood-that this disclosure is merely illustrative and that numerous changes may be made within the scope and spirit of the following claims.

I claim:

1. In apparatus of the class described, a router bit mounted for transverse movement; driving means connected with said route-r bit; two radius members pivotally connected with said router bit and extending in diametrically opposite directions therefrom; and anchor means positioned on opposite sides of said router bit in spaced relation-therefrom and operatively connected pivotally with said radius members and extending from one side of said radius members in trapezoidal form providing for horizontal movement of said radius members, said radius members and anchor means limiting the transverse movement of said router bit.

2. In apparatus of the class described, a substantially vertical driven flexible shaft; a router bit operatively connected with the lower end portion of said flexible shaft and supported thereby; two radius members pivotally connected with said router bit and extending in diametrically opposite directions therefrom; and anchor means positioned on opposite sides of said router bit in spaced relation therefrom and pivotally connected with the outer end portions of said radius members and providing for limited horizontal movement of said radius members and cooperating with said radius members limiting transverse movement of said router bit.

3. In apparatus of the class described, a support adapted for clamping engagement with material to be recessed, said support having an opening therein; a. router bit extending through said opening in said support andmovable transversely within said opening; driving means connected with said router bit; radius members pivotally connected with said router bit and extending in diametrically opposite directions therefrom and anchor means connected with said support at opposite sides of said router bit and operatively connected pivotally with said. radius members and providing for limited horizontal movement of said radius members, said radius members and anchor means limiting transverse movement of said router bit.

4. In apparatus of the class described, a fiat work clamping plate member having a relatively large opening therein; a router bit protruding through said opening and movable freely within said opening without contacting the plate member at the edges of said opening;.depending flexible shaft driving means connected with said router bit and forming a support therefor; two radius members pivotally connected with said router bit; and anchor means carried by said flat plate member positioned on opposite sides of said router bit and pivotally connected with the outer end portions of said radius members said anchor means providing for limited horizontal movement of said radius members relative to said plate member.

5. In apparatus of the class described, a work clamping plate member having an opening therein; arouter bit extending throughsaid opening and freely movable sidewise within said opening; vertically shiftable driving means connected with the shank portion of said router hit; two radius links pivotally connected with said router bit and extending sidewise in diametrically opposite directions therefrom; pivot means movably connecting the outer end portions of said radius links with said plate member, said anchor means providing for limited horizontal movement of said radius links relative to said plate member, said pivot means and radius links cooperating to provide limited transverse movement of said router bit; and manually operated bit moving means connected with said router bit.

6. In apparatus of the class described, a work clamping plate member having an opening therein; a router bit extending through said opening and freely movable sidewise within said opening; vertically shiftable driving means connected with the shank portion of said router bit; two radius links pivotally connected with said router bit and extending sidewise in diametrically opposite directions therefrom; pivot means movably connecting the outer end portions of said radius links with said plate member and providing limited horizontal movement of said radius links relative to said plate member; said pivot means and radius links providing for transverse movement of said router bit; means limiting the transverse movement of said router bit; and handle means connected with said router bit controlling the transverse movement of said router bit.

7. In apparatus of the class described, a work clamping plate member having an opening therein; a router bit extending through said opening and freely movable sidewise within said opening; vertically shiftable driving means connected with the shank portion of said router bit; two radius links pivotally connected with said router bit and extending sidewise in diametrically opposite directions therefrom; pivot means movably connecting the outer end portions of said radius links with said plate member and providing limited horizontal movement of said radius links relative to said plate member, said pivot means and radius links cooperating to provide transverse movement of said router bit; means limiting the transverse movement of said router bit; adjusting means for said movement limiting means; and manually operated bit moving means connected with said router bit.

8. In apparatus of the class described, a plate member having an opening therein; a router bit positioned in said opening and supported for transverse movement, said opening afiording clearance for the operation of said router bit; driving means connected with said router hit; two link members pivotally mounted on said plate member and extending on opposite sides of said router bit; two radius links pivotally connected with said link members and with the shank portion of said router bit; means limiting the swinging movement of said link members toward said router bit; and manually operated router bit moving means connected with said router bit.

9. In apparatus of the class described, a plate member having an opening therein; a router bit positioned in said opening and supported for transverse movement, said opening afiording clearance for the operation of said router bit; driving means connected with said router bit; two link members pivotally mounted on said plate member and extending on opposite sides of said router hit; two radius links pivotally connected with said link members and with the shank portion of said router bit; stop means limiting 35 swinging movement of said link members toward each other; adjusting devices connected with said stop means whereby the position of the stop means may be varied; and bit moving means connected with said router bit.

10. In apparatus of the class described, a relatively flat plate member having a relatively large opening therein; a fluid pressure cylinder secured to said plate member; a track member positioned above said plate member; a carriage movable on said track member; a rigid support extending downwardly from said carriage; a piston fixed to the lower end portion of said support and positioned within said cylinder; means controlling the admission of fluid under pressure to the respective end portions of said cylinder whereby said cylinder and. plate may be moved vertically; a bracket guided for vertical movement on said carriage; a motor mounted on said bracket; bracket supporting means connected with said bracket, said cylinder moving said bracket vertically synchronously with said cylinder; a flexible shaft depending from said motor, a router bit connected with the lower end portion of said flexible shaft and extending through the opening in said plate member and movable sidewise within said opening; two radius members pivotally connected with said router bit; anchor means carried by said plate member positioned on opposite sides of said router bit and pivotally connected with the outer end portions of said radius members providing for limited horizontal movement of said radius members relative to said plate member; and handle means connected with the lower end portion of said flexible shaft providing means for moving said router bit.

11. In apparatus of the class described, a relatively fiat plate member having a relatively large opening therein; a pneumatic cylinder secured to said plate member; supporting means positioned above said plate member; a rigid support extending downwardly from said supporting means; a piston fixed to the lower end portion of said support and positioned within said pneumatic cylinder; means controlling the admission of fluid under pressure to said cylinder whereby said cylinder and plate may be moved vertically; driving means mounted on said supporting means and vertically movable with said cylinder and plate member; a flexible shaft depending from said driving means; a router bit connected with the lower end portion of said flexible shaft and extending through the opening in said plate member and movable sidewise within said opening; two radius members pivotally connected with said router bit; anchor means carried by said plate member positioned on opposite sides of said router bit and pivotally connected with the outer end portions of said radius members providing for limited horizontal movement of said radius members relative to said plate member and handle means connected with the lower portion of said flexible shaft providing means for moving said router bit.

12. In apparatus of the class described, a table; upwardly extending supporting means movable longitudinally of said table; a horizontal track member on the upper end of said supporting means extending crosswise of said table; a carriage movable on said truck member; a fiat plate member having an opening therein; a fluid pressure cylinder secured to said plate member; a rigid support extending downwardly from said carriage; a piston fixed to the lower end portion of said support and positioned within said movable sidewise within said opening; two radius members pivotally connected with said router bit; anchor means carried by said plate member positioned on opposite sides of said router bit pivotally connected with the outer end portions of said radius members providing for limited horizontal movement of said radius members relative to said plate member, and handle means connected with the lower end portion of said flexible shaft providing means for moving 10 said router bit sidewise.

WILLIAM J. MILLER.

CERTIFICATE OF CORRECTION. Patent No. 2,o91,L 50. August 51, 1957.

WILLIAM J. MILLER.

It is hereby certified that the name of the assignee in the above numbered patent was erroneously written and printed as "Ellicott Bay Hill 00. whereas said name should have been written and printed as Elliott. Bay Hill Co. of Seattle, Washington, a corporation of Washington, as shown by the record of assignments in this office; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 16th day of November, A. D. 1957.

Henry Van Arsdale (Seal) Acting Commissioner of Patents. 

